A computational model for prediction of clot platelet content in flow-diverted intracranial aneurysms

Treatment of intracranial aneurysms with flow-diverting stents is a safe and minimally invasive technique. The goal is stable embolisation that facilitates stent endothelialisation, and elimination of the aneurysm. However, it is not fully understood why some aneurysms fail to develop a stable clot even with sufficient levels of flow reduction. Computational prediction of thrombus formation dynamics can help predict the post-operative response in such challenging cases. In this work, we propose a new model of thrombus formation and platelet dynamics inside intracranial aneurysms. Our novel contribution combines platelet activation and transport with fibrin generation, which is key to characterising stable and unstable thrombus. The model is based on two types of thrombus inside aneurysms: red thrombus (fibrin- and erythrocyte-rich) can be found in unstable clots, while white thrombus (fibrin- and platelet-rich) can be found in stable clots. The thrombus generation model is coupled to a CFD model and the flow-induced platelet index (FiPi) is defined as a quantitative measure of clot stability. Our model is validated against an in vitro phantom study of two flow-diverting stents with different sizing. We demonstrate that our model accurately predicts the lower thrombus stability in the oversized stent scenario. This opens possibilities for using computational simulations to improve endovascular treatment planning and reduce adverse events, such as delayed haemorrhage of flow-diverted aneurysms.

Ruptured posterior circulation aneurysms: epidemiology, patterns of care, and outcomes from the Swiss SOS national registry

BACKGROUND

The treatment of ruptured posterior circulation aneurysms remains challenging despite progresses in the endovascular and neurosurgical techniques.

OBJECTIVE

To provide epidemiological characterization of subjects presenting with ruptured posterior circulation aneurysms in Switzerland and thereby assessing the treatment patterns and neurological outcomes.

METHODS

This is a retrospective analysis of the Swiss SOS registry for patients with aneurysmal subarachnoid hemorrhage. Patients were divided in 3 groups (upper, lower, and middle third) according to aneurysm location. Clinical, radiological, and treatment-related variables were identified and their impact on the neurological outcome was determined.

RESULTS

From 2009 to 2014, we included 264 patients with ruptured posterior circulation aneurysms. Endovascular occlusion was the most common treatment in all 3 groups (72% in the upper third, 68% in the middle third, and 58.8% in the lower third). Surgical treatment was performed in 11.3%. Favorable outcome (mRS ≤ 3) was found in 56% at discharge and 65.7% at 1 year. No significant difference in the neurological outcome were found among the three groups, in terms of mRS at discharge (p = 0.20) and at 1 year (p = 0.18). High WFNS grade, high Fisher grade at presentation, and rebleeding before aneurysm occlusion (p = 0.001) were all correlated with the risk of unfavorable neurological outcome (or death) at discharge and at 1 year.

CONCLUSIONS

In this study, endovascular occlusion was the principal treatment, with a favorable outcome for two-thirds of patients at discharge and at long term. These results are similar to high volume neurovascular centers worldwide, reflecting the importance of centralized care at specialized neurovascular centers.

Multiple Aneurysms Clipping Through the Eyebrow Approach: 2-Dimensional Operative Video

The eyebrow approach is a versatile technique that may apply to various vascular and tumoral pathologies of the anterior skull base. We present a case of multiple aneurysms clipping through the eyebrow approach and we discuss the nuances of this technique. A 44-yr-old patient presented with incidentally found aneurysms. Angiography showed 2 4.5-mm aneurysms on the left middle cerebral artery (MCA) and internal carotid artery (ICA) bifurcations. At surgery, the patient is positioned supine with the head elevated, slightly rotated, and extended in order to obtain good access and gravity retraction of the brain. A 3-cm incision is placed in the eyebrow and a small supraorbital bone flap is raised. The floor of the orbit and the edges of the craniotomy are thoroughly drilled in order to maximize the working space. After dural opening, the sylvian fissure was widely dissected and the MCA aneurysm was identified. A large opening of the sylvian and carotid cistern allows retractor free surgery. The ICA bifurcation aneurysm is then dissected and clipped. The MCA aneurysm is treated last in order to avoid a conflict between instruments especially during clipping. Aneurysms occlusion and vessel permeability is verified by Doppler ultrasonography and indocyanine green (ICG) angiography. After achieving hemostasis, the dura is closed and a subcuticular continuous suture is used at the skin. The postoperative course was uneventful. The eyebrow approach allows simultaneous treatment of multiple aneurysms of the anterior circle of Willis in selected cases. Proper positioning, drilling of the orbital floor and extensive arachnoid dissection are the key steps of this procedure.

Platelet Function Testing in Neurovascular Procedures: Tool or Gimmick?

Background

Platelet inhibitors are used to prevent thromboembolic complications related to neurovascular stenting (NVS) procedures. Despite substantial inter-individual variability of functional platelet inhibition, the value of platelet function tests (PFT) to assess inhibition remains controversial.

Objective

This study was conducted to compare differences in thromboembolic complication rates associated with NVS in platelet-inhibited patients with and without PFT. Clinical neurological outcomes were assessed by differences in the modified Rankin Scale (mRS).

Materials and Methods

One hundred seventeen consecutive patients underwent elective NVS procedures within a 7-year period. All patients received aspirin and clopidogrel 8 days before the procedure. Fifty-two patients were treated without assessment of platelet inhibition, and 65 patients were tested for clopidogrel resistance. When clopidogrel resistance was revealed, corresponding patients were converted to ticagrelor. Changes in mRS and thromboembolic event rates were compared between the 2 cohorts.

Results

Thirty-five percent of patients from the cohort subjected to PFT tests showed inadequate platelet inhi-bition under clopidogrel and were converted to ticagrelor. Compared to the non-PFT test -cohort, neurological deficits were significantly reduced (12 vs. 0%; p = 0.009) and a lower number of thromboembolic events was found (12 vs. 3%; p > 0.05) within the test cohort.

Conclusion

PFT appears to identify patients with clopidogrel resistance prior to NVS procedures. When non-responders are converted to alternative platelet inhibitors, neurological outcomes and thromboembolic complication rates may improve. Consequently, this study provides preliminary evidence that PFT may be a useful clinical tool to enhance procedural safety and improve clinical outcomes in NVS procedures.

Efficiency and complications of Woven EndoBridge (WEB) devices for treatment of larger, complex intracranial aneurysms-a single-center experience

BACKGROUND

Several recently published multicenter studies have reported high treatment feasibility, high safety, and good 6-month to 1-year efficiency when treating smaller intracranial aneurysms (IA) with WEB deployment. The purpose of the study was to evaluate the long-term efficiency and complications related to WEB treatment of larger, complex intracranial aneurysms in a small single-center cohort.

METHODS

Patients with ruptured and unruptured IA were treated with WEB devices; data were collected prospectively and analyzed retrospectively. The study evaluates complications and clinical and radiological findings at immediate and last available follow-up.

RESULTS

The study included 16 patients with 16 aneurysms and a median follow-up time of 36 months, range 13-49 months; 9/16 were females. Median age 59 with range 39-71 years. Mean aneurysm size 11.3 ± 1.7 mm, predominant location at the basilar artery bifurcation and anterior communicating artery. Three out of sixteen IAs were ruptured. Even though 75% of the IAs were immediately occluded completely, retreatment was eventually necessary in 7/15 (46.7%). Increasing neck remnants and recurrences were mainly observed past 1-year follow-up. The WEB device showed modifications over time, with six devices showing signs of compression in the long term. There was one fatality due to aneurysm rupture after 4 years.

CONCLUSIONS

The long-term efficiency of WEB deployment in larger, complex aneurysms is low with about half of the cases needing at least one retreatment. A large fraction of WEB collapse past 1-year follow-up.

Increased tooth brushing frequency is associated with reduced gingival pocket bacterial diversity in patients with intracranial aneurysms

Objectives

The objective of this study was to investigate the association of tooth brushing frequency and bacterial communities of gingival crevicular fluid in patients subjected to preoperative dental examination prior to operative treatment for unruptured intracranial aneurysms.

Methods

Gingival crevicular fluid samples were taken from their deepest gingival pocket from a series of hospitalized neurosurgical patients undergoing preoperative dental screening (n = 60). The patients were asked whether they brushed their teeth two times a day, once a day, or less than every day. Total bacterial DNA was isolated and the V3–V4 region of the 16S rRNA gene was amplificated. Sequencing was performed with Illumina’s 16S metagenomic sequencing library preparation protocol and data were analyzed with QIIME (1.9.1) and R statistical software (3.3.2).

Results

Bacterial diversity (Chao1 index) in the crevicular fluid reduced along with reported tooth brushing frequency (p = 0.0002; R2 = 34%; p (adjusted with age and sex) = 0.09; R2 = 11%) showing that patients who reported brushing their teeth twice a day had the lowest bacterial diversity. According to the differential abundant analysis between the tooth brushing groups, tooth brushing associated with two phyla of fusobacteria [p = 0.0001; p = 0.0007], and one bacteroidetes (p = 0.004) by reducing their amounts.

Conclusions

Tooth brushing may reduce the gingival bacterial diversity and the abundance of periodontal bacteria maintaining oral health and preventing periodontitis, and thus it is highly recommended for neurosurgical patients.

Efficacy and safety of prasugrel therapy for intracranial aneurysms with endovascular treatment: A meta-analysis

BACKGROUND

Prasugrel as a second generation P2Y12 adenosine diphosphate receptor antagonist which in the cerebral aneurysms with Endovascular treatment have become more emphasized.

OBJECTIVE

To compare the efficacy and safety of prasugrel therapy for intracranial aneurysms with endovascular treatment.

METHODS

The databases of PubMed, Embase, Cochrane Library databases and China Biology Medicine disc were retrieved with computers for collecting controlled trials about the comparison in the efficacy and safety of prasugrel and clopidogrel published from inception to September 2018. At the same time, the reference materials of included literature were retrieved manually. After rigorous evaluation on literature quality, the eligible data of the trials was extracted and given a Meta-analysis by applying RevMan5.3 software.

RESULTS

Of the 96 studies identified, 7 trials were included. Results of meta-analysis showed that compared with patients receiving clopidogrel treatment, novel platelet P2Y₁₂ receptor inhibitor prasugrel were effective in reducing the incidence of thromboembolic events (OR = 0.19, 95%CI: 0.08-0.45, P = .0001), but did not increase the risk of hemorrhagic complication (OR = 1.00, 95%CI: 0.53-1.89, P = 1.00), and the PRU (OR = 0.19, 95%CI: 0.08-0.45, P = .0001) and Percentage inhibition of platelet (MN = 37.05, 95%CI: 33.37-40.73, P < .00001) were controlled in a better range.

CONCLUSION

In antiplatelet therapy after aneurysmal interventional therapy, the second generation of P2Y₁₂ adenosine receptor antagonist prasugrel can significantly reduce the risk of thrombosis without increasing the risk of bleeding.

Collagen COL22A1 maintains vascular stability and mutations in COL22A1 are potentially associated with intracranial aneurysms

Collagen XXII (COL22A1) is a quantitatively minor collagen, which belongs to the family of fibril-associated collagens with interrupted triple helices. Its biological function has been poorly understood. Here, we used a genome-editing approach to generate a loss-of-function mutant in zebrafish col22a1. Homozygous mutant adults exhibit increased incidence of intracranial hemorrhages, which become more prominent with age and after cardiovascular stress. Homozygous col22a1 mutant embryos show higher sensitivity to cardiovascular stress and increased vascular permeability, resulting in a greater percentage of embryos with intracranial hemorrhages. Mutant embryos also exhibit dilations and irregular structure of cranial vessels. To test whether COL22A1 is associated with vascular disease in humans, we analyzed data from a previous study that performed whole-exome sequencing of 45 individuals from seven families with intracranial aneurysms. The rs142175725 single-nucleotide polymorphism was identified, which segregated with the phenotype in all four affected individuals in one of the families, and affects a highly conserved E736 residue in COL22A1 protein, resulting in E736D substitution. Overexpression of human wild-type COL22A1, but not the E736D variant, partially rescued the col22a1 loss-of-function mutant phenotype in zebrafish embryos. Our data further suggest that the E736D mutation interferes with COL22A1 protein secretion, potentially leading to endoplasmic reticulum stress. Altogether, these results argue that COL22A1 is required to maintain vascular integrity. These data further suggest that mutations in COL22A1 could be one of the risk factors for intracranial aneurysms in humans.

Summary: Collagen COL22A1 is expressed in perivascular fibroblast-like cells and is required to maintain vascular stability in a zebrafish model. Mutations in COL22A1 are likely to be associated with intracranial aneurysms.

The classification of intracranial aneurysm neck: a single center research experience

BACKGROUND

There is associating with incidence of unfavorable outcomes compared to microsurgical clippings. We are in order to investigate the outcomes of microsurgical clipping for intracranial aneurysms and determine the ideal clipping methods for different aneurysm subtypes.

METHOD

Retrospectively analyzed the clinical characteristics and follow-up data (completely recorded) of 123 patients with 128 aneurysms were treated. 20 cases were treated as control group from October 2013 to December 2013. Since January 2014, aneurysms were classified base on the 20 cases of aneurysm imaging data. 103 patients were treated as experimental group, the classification of aneurysms previously proposed was used to estimate the way of surgery, and the guiding value of the genotype was verified according to the intraoperative findings. The proposed aneurysm classification is based on the virtual surface of the aneurysm and the parent artery, the aneurysm neck was classified as follows: subtype I, the curved surface of the neck is a single curved surface; subtype II, the neck is hyperboloid; subtype III, neck is a three-curved surface. Aneurysms were divided into further subtypes according to the ratio of the width of the aneurysm neck surface and the length of the artery circumference: subtype A, the ratio of the aneurysm neck surface to the parent artery was not more than 0.5; subtype B, more than 0.5. There are some clamping methods include simple, sliding, interlocking and hybrid.

RESULTS

In the control group, patients did not undergo a suitable clipping scheme without classification of aneurysm neck (unclassed clipping). While causing the occurrence of occlusion adverse events, including neck residual, Tumor artery stenosis, electrophysiological changes, the lack of blood supply and so on. The experimental[page1image12073600]group was analyzed by using a predetermined clipping scheme (classed clipping), and the use of aneurysms clamps was approximately the same as expected. Compared the preoperative assessment with the actual situation, the consistency of the control group was 50% and the experimental group was 96%. Adverse events of classed clipping is 2%, another is 60%. There is a significant difference between the two groups (P < 0.05).Classed clipping of subject IA and IB are simple (mean 1.2 and 1.3 clips); classed clipping of subject IIA is simple and interlocking(mean 1.2 clips); classed clipping of subject IIB is sliding and hybrid(mean 2.05 clips); classed clipping of subject IIIA and IIIB are hybrid(mean 2.3 clips).

CONCLUSION

There is a higher consistency in surgery through the above classification of preoperative assessment of clipping. There was no adverse event of intracranial aneurysm clipping in the clipping mode selected by the above classification, and satisfactory surgical clipping rate was achieved and no recurrence was found.

Regulatory T cells demonstrate significantly increased functions following stimulation with IL-2 in a Tim-3-dependent manner in intracranial aneurysms

The formation of intracranial aneurysm (IA) is associated with the destruction of various cellular and structural components, which induces pathogenic inflammatory responses that further propagate tissue damage. The regulatory immune system can suppress exacerbated inflammation and offer tissue protection; however, previous studies by others and us have demonstrated that the regulatory T (Treg) cells were functionally impaired in IA patients. Hence, strategies that can improve Treg function in IA patients should be investigated. Based on our previous finding that IL-2 strongly elevated the expression of the checkpoint molecule Tim-3 in Treg cells, we examined the effect of IL-2 in the function of Treg cells from IA patients. External IL-2 significantly improved the proliferation of Treg cells, increased the expression of CTLA-4 and LAG-3, and enhanced Treg-mediated suppression of conventional T cell (Tconv) proliferation. Importantly, compared to the Tim-3^- Treg cells, the Tim-3⁺ Treg cells presented comparable proliferation capacity, but significantly greater expressions of CTLA-4 and LAG-3 and significantly higher capacity to suppress Tconv proliferation. In addition, blocking Tim-3 abrogated IL-2-mediated enhancement of Tim-3⁺ Treg cells. We then investigated the IL-2 level in IA patients, and found that although IA patients and healthy controls presented similar serum IL-2 concentration, the concentrations of IL-1β and TNF-α were significantly higher in IA patients than in healthy controls, signaling a relative reduction in IL-2 abundance. Together, we found that IL-2 could significantly enhance the function of Treg cells from IA patients in a Tim-3-dependent manner.

Expression profile analysis of differentially expressed genes in ruptured intracranial aneurysms: In search of biomarkers

Intracranial aneurysms (IAs) result from the bulging of arterial walls secondary to several factors such as flow, vessel morphology, and genetics. Subarachnoid hemorrhage occurs when such walls rupture, leading to high disability and mortality. Despite numerous investigations pertaining to the relationship between geometric characteristics and IA rupture, only a few have obtained consistent results. This study aimed to further identify the potential genes associated with the pathogenesis of IAs, which may provide novel molecular biomarkers. We downloaded and reanalyzed six datasets, which were divided into four groups. IA walls and blood samples were screened for differentially expressed genes (DEGs); then, functional and pathway enrichment analyses were conducted. In total, 158 common DEGs were identified from Groups 1-3 and 396 genes (187 upregulated and 209 downregulated genes) were differentially expressed in Group 4. The functional analysis revealed that the DEGs were mainly associated with the major histocompatibility complex class II protein complex and antigen processing and presentation. Finally, we identified nine key genes, both in aneurysm tissue samples and blood samples, of which three were mostly associated with the progression and rupture of IAs. Bioinformatics was used to analyze the datasets of the ruptured IAs and identify potential biomarkers, which may provide information for the early detection and treatment of IAs.

Hydrogel coils versus bare platinum coils for the endovascular treatment of intracranial aneurysms: a meta-analysis of randomized controlled trials

Background

Recent studies have shown conflicting results regarding the effect of hydrogel coils for treating intracranial aneurysm compared to bare platinum coils. We implemented a meta-analysis to assess the value of hydrogel coils in intracranial aneurysm treatment.

Methods

The MEDLINE, EMBASE, and Cochrane Library databases were searched for randomized controlled trials (RCTs) which had evaluated hydrogel coils versus bare platinum coils for intracranial aneurysms.

Results

We pooled 1526 patients from 4 RCTs with the mean follow-up time of more than 16 months. Hydrogel coils had reductions on mid-term recurrence (RR 0.78, 95% CI 0.65 to 0.94, P = 0.008) and residual aneurysm (RR 0.71, 95% CI 0.57 to 0.88, P = 0.002), but didn’t show any significant differences in other favorable outcomes such as functional recovery, mortality and so on. In the subgroup analysis, we found that second-generation hydrogel coils might exhibit potential impacts on increasing mid-term complete occlusion (RR 1.26, 95% CI 1.07 to 1.48, P = 0.005) and decreasing residual aneurysm neck. (RR 0.54, 95% CI 0.34 to 0.86, P = 0.010).

Conclusions

Hydrogel coils showed no significant efficacy on functional recovery but exhibited a lower rate of recurrences and residual aneurysms in patients with intracranial aneurysms.

Electronic supplementary material

The online version of this article (10.1186/s12883-018-1171-8) contains supplementary material, which is available to authorized users.

Surgical treatment and perioperative management of intracranial aneurysms in Chinese patients with ischemic cerebrovascular diseases: a case series

BACKGROUND

Patients with ischemic cerebrovascular diseases are more likely to suffer from intracranial aneurysms, and their surgical treatment has a growing controversy in this condition. The current case series was aimed at exploring surgical treatment and perioperative management of intracranial aneurysms in Chinese patients with ischemic cerebrovascular diseases.

METHODS

Minimally invasive surgical approach through small pterion or inferolateral forehead was applied in 31 patients. Anti-platelet drugs were withdrawn 1 week before surgical operation. Systolic blood pressure was controlled to be more than 110 mmHg and increased by 20% after the clipping of intracranial aneurysms. Branches of external carotid artery were spared to ensure collateral circulation. Temporary blocking was minimized and ischemic time was shortened during surgical operation.

RESULTS

Patients had an average age of 66 (46-78) years, and proportion of males was 39% (12 males). There were 35 unruptured intracranial aneurysms with a diameter more than 5 mm. There were 20 posterior communicating and anterior choroidal aneurysms (57%), seveb middle cerebral aneurysms (20%), and eight anterior communicating aneurysms (23%), with 21 lobular aneurysms (60%). Twenty-nine patients had normal neurological function (Glasgow Outcome Scale [GOS] 5), one patient with mild neurological defect (GOS 4), and one patient with severe neurological defect (GOS 3) at discharge. Meanwhile, there were 26 patients with modified Rankin Scale (MRS) 0-1, 4 patient with MRS 2, and one patient with MRS 3 at discharge. There were four patients lost during the follow-up. During the follow-up, 26 patients had normal neurological function (GOS 5), and one patient with severe neurological defect (GOS 3). Meanwhile, there were 25 patients with MRS 0-1, one patient with MRS 2, and one patient with MRS 3. All patients had no recurrence of intracranial aneurysms after operation.

CONCLUSIONS

The current case series found that minimally invasive surgical approach and intraoperative monitoring, supplemented by effective management of cerebrovascular perfusion, circulation and coagulation, can promote the treatment of intracranial aneurysms and prevent the development of cerebral ischemia and aneurysm rupture in Chinese patients with ischemic cerebrovascular diseases. Future studies with large sample size will be needed to confirm the results from the current case series.

Pediatric intracranial aneurysms: changes from previous studies

PURPOSE

To develop a better understanding of pediatric intracranial aneurysms (PIAs).

METHODS

All PIAs treated in our center from January 2012 to April 2017 were retrospectively included. Clinical data, treatment summaries, and follow-up outcomes were retrieved and analyzed.

RESULTS

A total of 66 PIAs were found in 64 patients with a mean age of 11.4 ± 5.7 years, 68.8% of whom were male. The most common symptoms were seizure (n = 7, 63.6%) for the 0-5 age group and headache (n = 38, 71.7%) for the 6-18 age group. Fifty-one PIAs (77.3%) were located in the anterior circulation, with the middle cerebral artery (MCA) being the most common site (n = 28, 42.4%). Fifteen patients (23.4%) had PIAs that were pseudoaneurysms, and nine of them (60%) had a combined history of head trauma. Thirty-five patients (54.7%) had distal arterial aneurysms, and 21 of them (60%) presented with seizure. During a mean follow-up time of 1.6 ± 1.2 years, 79.7% of patients (n = 51) had favorable outcomes, 5 patients (7.8%) died, and the remaining 8 patients (12.5%) had unfavorable outcomes with severe neurological deficits.

CONCLUSION

Apart from characteristics consistent with previous studies, several new findings regarding PIAs were reported, including a difference in the most common symptoms in different age groups, the MCA as the predominant location of PIAs, the high ratio of pseudoaneurysms and their head trauma etiology, and the incidence of distal arterial aneurysms and their relationship with the risk of seizures.

High-Density Lipoprotein Is Associated with Progression of Intracranial Aneurysms

BACKGROUND

We tested the hypothesis that high-density lipoprotein (HDL) is associated with intracranial aneurysm growth and rupture.

METHODS

We used an observational cohort study design. Age, sex, admission systolic blood pressure (SBP), diabetes, hypertension, coronary artery disease, aneurysmal rupture, apolipoprotein (APO)-A1, APO-B, HDL, low-density lipoprotein, triglycerides, cholesterol, and aneurysm location and size were recorded. Aneurysms <8 mm were categorized as small.

RESULTS

The data from 581 patients with intracranial aneurysms were analyzed. The predictive factors for small size of aneurysms were female sex (odds ratio [OR], 0.630; 95% confidence interval [CI], 0.428-0.927; P = 0.019) and higher HDL (OR, 0.327; 95% CI, 0.159-0.672; P = 0.0002). In the subgroup of male patients, lower HDL was the only risk factor for large size (P = 0.015). The predictors of aneurysmal rupture were small size (OR, 0.875; 95% CI, 0.842-0.910; P = 0.000), higher HDL (OR, 3.716; 95% CI, 1.623-8.509; P = 0.002), no coronary artery disease (OR, 4.736; 95% CI, 1.528-14.681; P = 0.007), lower APO-A1 (OR, 0.202; 95% CI, 0.064-0.641; P = 0.007), and higher admission SBP (OR, 1.024; 95% CI, 1.015-1.032; P = 0.000). An HDL/aneurysm size ratio >0.31 was associated with a 46.2-fold increased likelihood of aneurysmal rupture (OR, 46.214; 95% CI, 13.386-159.548; P = 0.002).

CONCLUSIONS

The HDL level was inversely associated with intracranial aneurysm growth, especially in men. Higher HDL levels and small aneurysm size contributed to a greater risk of aneurysmal rupture. An HDL/size ratio >0.31 was a valuable predictor of intracranial rupture.

The role of inflammation and potential pharmacological therapy in intracranial aneurysms

Intracranial aneurysms remain important clinical concern. There is relatively low risk of rupture of symptomless aneurysms incidentally found in MRA or CTA performed due to other indications. Not all of the intracranial aneurysms should or can be treated with neurosurgery intervention or endovascular embolization. Clinical strategy for small, symptomless, unruptured aneurysms is still questionable. Mechanisms underlying aneurysms formation, progression and rupture are poorly understood. Inflammation is one of the factors suspected to participate in these processes. Therefore the aim of this manuscript is to present current state of knowledge about the role of inflammation in the formation and progression of intracranial aneurysms and in their rupture process. Current knowledge about possible pharmacological treatment of intracranial aneurysms will also be presented. Macrophages infiltration seems to participate in the formation of intracranial aneurysms. Inhibition of signals sent by macrophages may prevent the aneurysms formation. Inflammation present in the wall of the aneurysm seems to be also related to the aneurysm's rupture risk. However it does not seem to be the only cause of the degeneration, but it can be a possible target of drug therapy. Some preliminary studies in humans indicate the potential role of aspirin as a factor that decrease the level of inflammation and lower the risk of rupture of intracranial aneurysms. However further research including a greater number of subjects and a prospective randomized design are necessary to assess the role of aspirin in preventing strategy for small, symptomless, unruptured intracranial aneurysms.

Radiologic Characteristics and High Risk of Seizures in Infants with Ruptured Intracranial Aneurysms: Case Report and Review of the Literature

OBJECTIVE

To evaluate the parameters related to the high risk of preoperative seizures in infants (1 year or younger) with ruptured intracranial aneurysms.

METHODS

Infants with ruptured intracranial aneurysms treated at our institution from January 2012 to January 2018 were retrospectively analyzed. Seventeen similar cases of infant patients with seizures reported in published studies were reviewed.

RESULTS

The mean age of the 7 infant patients treated at our institution was 4.1 ± 3.3 months (range, 28 days to 11 months), with 2 male and 5 female subjects. One patient (14.3%) had an internal carotid artery aneurysm with subarachnoid hemorrhage, and the remaining 6 patients (85.7%) had middle cerebral artery (MCA) aneurysms in the distal arterial region with lobe hemorrhage. Five of the 7 infants (71.4%) had seizures, 4 of whom (4/5, 80.0%) had MCA distal arterial aneurysms with lobe hemorrhage. Management was successful for all patients with aneurysm clipping or resection surgery, and one patient experienced postoperative seizures. Of the 17 reviewed cases of infant patients with seizures, 10 patients (58.8%) exhibited the typical distal arterial aneurysm with lobe hemorrhaging, and 6 (60%) of them had aneurysms in MCA.

CONCLUSIONS

Infant patients with ruptured intracranial aneurysms have a high risk of preoperative seizures. The typical radiologic finding of distal arterial aneurysm with lobe hemorrhage was frequently observed in the MCA, and it might be related to the high risk of preoperative seizures in this population. Microsurgical techniques effectively control postoperative seizures in infants with ruptured intracranial aneurysms.

Ventriculostomy-related hemorrhage in patients on antiplatelet therapy for endovascular treatment of acutely ruptured intracranial aneurysms. A meta-analysis

The risk of ventriculostomy-related hemorrhage among patients requiring antiplatelet therapy (AT) for the endovascular treatment of acutely ruptured intracranial aneurysms needed further investigation. The authors performed a systematic review and meta-analysis of the literature examining the EVD-related hemorrhage rate among patients with and without AT (controls). According to PRISMA guidelines, a comprehensive review of studies published between January 1990 and April 2018 was carried out. The authors identified series with > 5 patients reporting the EVD-associated hemorrhage rate among the AT group and the control group. Variables influencing outcomes were analyzed using a random-effects meta-analysis model. We included 13 studies evaluating 516 (with AT) and 647 (without AT) patients requiring ventriculostomy. EVD-related hemorrhage rates were higher among the AT group (125/516 = 20.9%, 95% CI = 11.9-30%, I² = 90% vs 57/647 = 9%, 95% CI = 5.5-12.5%, I² = 45.8%) (p < 0.0001). Major EVD-associated hemorrhage rates were low in both the AT and control group (25/480 = 4.4%, 95% CI = 1.7-7.7%, I² = 53.9% vs 6/647 = 0.7%, 95% CI = 0.03-1.7%, I² = 0%) (p < 0.0001). Ventriculostomy before embolization and intraprocedural AT were associated with lower rates of EVD-related bleeding (32/230 = 9.6%, 95% CI = 2.1-17.1%, I² = 75.4% vs 6/24 = 25.1%, 95% CI = 8.8-41%, I² = 0%) (p < 0.02). The rate of major hemorrhage was higher after dual AT (CP + ASA) compared to single AT (ASA or CP) used as an intraprocedural loading dose (13/173 = 7%, 95% CI = 3.3-10.7%, I² = 0% vs 6/210 = 1.7%, 95% CI = 0.1-3.4%, I² = 0%) (p < 0.009). AT during endovascular treatment of acutely ruptured intracranial aneurysms increases the risk of EVD-related hemorrhages, although most of them are small and asymptomatic. When ventriculostomy is performed before endovascular procedures requiring antiplatelet administration, the hemorrhagic risk is minimized. A single antiplatelet therapy is associated with a lower rate of major bleeding than a dual therapy.

Evaluation of the risk of rupture of intracranial aneurysms in patients with aneurysmal subarachnoid hemorrhage according to the PHASES score

The PHASES score was developed to determine the risk of rupture of un-ruptured intracranial aneurysms (UIAs). The purposes of the current study were to apply this score on patients with actually ruptured intracranial aneurysms and to analyze the hypothetically prediction of the risk in this particularly patient group. We extracted the data of 100 recently treated patients (23 male, 77 female, mean age 56.4 years, range 17-93 years) with ruptured saccular intracranial aneurysms from our prospectively maintained neurovascular database according to the parameters used in the PHASES score (population, hypertension, age, earlier SAH, size and site of the aneurysm). Descriptive statistical analysis was performed using SPSS for Windows version 18.0 (SPSS Inc., Chicago, Illinois, USA). Ninety-nine percent of the patients were European and 1% Japanese in our series. Pre-existing arterial hypertension was found in 59%. Fifteen percent of the patients were > 75 years. Earlier SAH was found in 1%. The site of the aneurysms were the internal carotid artery (ICA) in 10%, the middle cerebral artery (MCA) in 14%, and arteries of the anterior and posterior circulation (PC) including the posterior communicating artery (PCOM) in 76%. Sixty-six percent of the aneurysms were smaller than 7 mm, 18% ranged between 7 and 9.9 mm, 14% were between 10 and 19.9 mm, and 2% were larger than 20 mm. European population, aneurysm size < 7 mm, and age < 75 years scored with 0 point in the PHASES study occurred most frequently in our series. The distribution of the aneurysm site to the anterior and posterior circulation scored with 4 points occurred most frequently. Considering the 5-year risk of rupture, 70% of our patient collective would have an estimated risk of < 2%. Interestingly, 70% of the patients with aneurysmal SAH had a low risk profile and would have a low risk of rupture according to the PHASES score in our series. This observation underlines the discrepancy of the estimated low risk of rupture for UIAs in young and healthy patients and the obvious fact the majority of the SAH patients are actually young with low risk factors. Parameters beyond the features of the PHASES score are needed to determine the risk of rupture of intracranial aneurysms.

Safety and efficacy of a new outreach distal access catheter, TACTICS, for coil embolization of unruptured intracranial aneurysms

Background and purpose Current large-bore catheters can be easily and safely placed in the intracranial vessels for the stabilization of microcatheters in several neurointervention scenarios. We considered that a novel 3.4 French catheter (TACTICS, Technorat Corporation, Aichi, Japan) might be useful for intermediate/distal access in a triaxial system. Here, we present our initial experience using the TACTICS catheter for treatment of intracranial aneurysms. Materials and methods A total of 35 endovascular coils were placed to embolize unruptured intracranial aneurysms of the anterior circulation using the TACTICS catheter between December 2016 and November 2017. These procedures were retrospectively reviewed to assess aneurysmal obliteration (Raymond's classification), the volume embolization ratio (VER) and procedural complications in comparison with 96 conventional coil treatments during the 3-year period up to 2016. Data were matched for aneurysmal morphology (location, maximum diameter and aspect ratio) by the propensity method. Results In all procedures, the TACTICS catheter was atraumatically landed beyond the carotid siphon. There were no hemorrhagic or symptomatic ischemic complications. After propensity matching, 68 procedures were assessed (34 in each group). Achievement of Raymond's scale 1 (complete occlusion) showed the same frequency in both groups (50% vs. 50%, p = 0.23). The VER was significantly higher with the TACTICS catheter than with the conventional method (34.0% vs. 28.7%, p = 0.003). Conclusion We reviewed our initial experience of the TACTICS catheter. It can be used as an intermediate catheter for safe and effective endovascular coil embolization of anterior circulation aneurysms.

A clinical study and meta-analysis of carotid stenosis with coexistent intracranial aneurysms

Carotid stenosis (CS) and intracranial aneurysms (IAs) may concur in one person. We studied the prevalence of IAs in CS patients in our retrospectively collected database and systematically reviewed this issue. Five hundred and fifty-seven CS (≥50%) patients confirmed by DSA in our hospital from 2010-06 to 2015-06 were screened for coexistent IAs. After searching the related literatures from English and Chinese journal literature databases, a meta-analysis was performed to pool the prevalence of CS with coexistent IAs. Subgroup analyses were performed to explore the causes of heterogeneity among studies. IAs were detected in 98(17.0%) out of the 577 CS patients. 12 literatures and the present study including a total of 6965 CS patients and 446 cases with coexistent IAs. The pooled prevalence of CS with coexistent IAs was 6.3% (95%CI: 4.2-8.3%) in all the CS patients. The pooled RR for female to male CS patients to have coexistent IAs was 1.67 (95%CI: 1.34-2.08, P = 0.000). 3 studies and the present study were carried out in Asian countries with a pooled prevalence of 10.8% (95%CI: 5.3-16.3%); 6 studies in European countries with 3.0% (95%CI: 2.2-3.7%); and 3 studies in USA with 6.0% (95%CI: 2.2-9.7%). There was a statistically significant difference between the three subgroups (P < 0.001). The prevalence of IAs in CS patients seems higher in our clinical study and the meta-analysis than in the general population and previously reported. The eastern and the women CS patients have a higher risk for coexistent IAs.

Treatment of Intracranial Aneurysms with the Pipeline Embolization Device Only: a Single Center Experience

Purpose

The aim of this study was to evaluate the technical feasibility and rate of mid-term occlusion in aneurysms treated solely with the Pipeline Embolization Device (PED) in a German tertiary care university hospital.

Materials and Methods

Forty-nine non-consecutive intracranial aneurysms underwent endovascular treatment using the PED exclusively between March 2011 and May 2017 at our institution. Primary endpoint was a favorable aneurysm occlusion defined as OKM C1-3 and D (O'Kelly Marotta Scale). Secondary endpoints were retreatment rate and delayed complications. Median follow-up was 200 days.

Results

The mean aneurysm size was 7.1 ± 5.3 mm. Forty-four aneurysms were located in the anterior circulation (90%). Ten aneurysms were ruptured (20%). Branching vessels from the sac were observed in 11 aneurysms (22%). Favorable obliteration immediately after PED placement was seen in 13/49 aneurysms (27%), of those nine aneurysms were completely occluded (18%). Angiographic and clinical follow-up was available for 45 cases (92%); 36/45 aneurysms (80%) were occluded completely and 40/45 aneurysms (89%) showed a favorable occlusion result. A branching vessel arising from the aneurysm sac was associated with incomplete occlusion (P < .05). All electively treated patients had good outcome (mRS 0). Three aneurysms (6%) required additional treatment due to aneurysm recurrence.

Conclusion

In our series, treatment of intracranial aneurysms with the PED was associated with favorable occlusion rates and low complication rates at mid-term follow-up. The presence of branching vessels arising from the aneurysms sac was predictive for an incomplete occlusion.

The angiographic and clinical outcomes of intracranial aneurysms following irradiation in patients with nasopharyngeal carcinoma: A 13-year experience and literature review

BACKGROUND AND PURPOSE

Intracranial aneurysms are a known but rare complication of radiotherapy (RT). We reviewed the angiographic and clinical outcomes of intracranial aneurysms following RT in patients with nasopharyngeal carcinoma (NPC), a malignancy endemic in Hong Kong.

MATERIALS AND METHODS

The clinical, angiographic and laboratory data was collected for nine NPC patients harboring fifteen intracranial aneurysms following RT, diagnosed between 1st January 2000 and 31st December 2012.

RESULTS

The median age at aneurysm diagnosis was 56 years with a male predilection (67%). The median latent period to diagnosis was nine years (0.3-30). Eight patients (89%) presented with aneurysmal subarachnoid hemorrhage. Nine aneurysms were located at the anterior circulation, and 14 were saccular in morphology. Of the treated aneurysms, eight underwent endovascular intervention and two were surgically clipped. Within a year, 50% of the treated aneurysms had recurred. Poor neurological outcome was noted. At two-year follow-up, the median score for modified Rankin score and Glasgow Outcome score was 5 and 2 respectively. The two-year mortality rate of patients with treated ruptured intracranial aneurysms was 50%.

CONCLUSION

Compared to previous studies, our irradiated NPC patients had higher mortality and morbidity rates after aneurysm rupture and a higher angiographic recurrence rate following treatment. Greater vigilance is required in the detection of post-treatment recurrence of these aneurysms due to the higher risk of rupture. The authors recommend dedicated screening of intracranial aneurysms by active surveillance in routine CT protocols or the addition of three-dimensional time-of-flight magnetic resonance angiography in MR protocols.

A Systematic Review and Meta-Analysis on Economic Comparison Between Endovascular Coiling Versus Neurosurgical Clipping for Ruptured Intracranial Aneurysms

OBJECTIVE

Healthcare expenditures and cost reduction have been under critical surveillance in all countries and are critical for policymakers. This review aims at qualitatively and quantitatively analyzing the difference of hospital costs and length of stay between endovascular coiling versus neurosurgical clipping in ruptured intracranial aneurysms (RAs).

METHODS

MEDLINE, the Cochrane database, Embase, and the Web of Science database were searched and evaluated independently by 2 authors according to the Newcastle-Ottawa Scale for cohort studies describing economic hospital cost or length of stay in patients with RAs.

RESULTS

A total of 8 studies were included, describing 24,219 RAs treated with neurosurgical clipping and 24,962 RAs with endovascular coiling. Meta-analysis revealed that the total hospital costs (THCs) were similar between coiling versus clipping in RAs (standard mean difference [SMD], -0.05; 95% confidence interval [CI], -0.12 to 0.22; I² = 99%; P = 0.50). Subgroup analysis showed that THCs of clipping and coiling were similar in ruptured aneurysms in the United States. However, in South Korea, the THCs of coiling were significantly higher than clipping. In the long run, 1-year medical costs of endovascular treatment were significantly lower than that of clipping in RAs (SMD, 0.15; 95% CI, 0.05-0.25; I² = 66%; P = 0.005). In addition, the length of stay of coiled patients was significantly shorter than clipped patients (SMD, 0.29; 95% CI, 0.13-0.45; I² = 96%; P < 0.001).

CONCLUSIONS

Medical costs were region-specified. In the United States, total hospital costs and 1-year medical costs were similar in RA patients treated with endovascular coiling and neurosurgical clipping. However, in countries like South Korea and China, coiling was more expensive. The length of stay was much shorter in coiled patients in all countries.

Giant and Very Large Intracranial Aneurysms: Surgical Strategies and Special Issues

Giant intracranial aneurysms (GIAs) and very large intracranial aneurysms (VLAs) have a poor natural history because of a high incidence of bleeding and strokes. These lesions always represent a great challenge for neurosurgeons and interventional neuroradiologists because of some peculiar intrinsic features such as size, angioarchitecture, wide neck, mass effect, intraluminal thrombosis, atherosclerotic changes, involvement of branches and perforators, and a frequent need to perform revascularization procedures. The results of a cumulative surgical series of 75 VLAs and GIAs are reported. Thirty-three aneurysms were unruptured. Sixty aneurysms underwent direct surgical treatment consisting of 56 direct clippings, 3 trappings w/o revascularization, and 1 wrapping. Fifteen aneurysms were treated by means of extracranial to intracranial (EC-IC) high-flow bypass. An mRS score ranging between 0 and 2 was observed in 54 patients, whereas an mRS of 3 was seen in 5 patients. Four patients had a severe disability (mRS 4-5) and six patients died. Aneurysm's fragmentation, with stacking and seating clips, thrombectomy, and aneurysmorrhaphy were the techniques most frequently employed. Revascularization options involving EC-IC high-flow bypass were used in cases not amenable for direct treatment. Some technical tips and special issues related to the surgical management of these complex lesions are discussed.

The Use of Flow Diverter in Ruptured, Dissecting Intracranial Aneurysms of the Posterior Circulation

OBJECTIVE

Acute dissecting aneurysms of the posterior circulation are a rare cause of subarachnoid hemorrhage. Established endovascular treatment options include parent artery occlusion and stent-assisted coiling, but appear to be associated with an increased risk of ischemic stroke. Vessel reconstruction with flow diverters is an alternative treatment option; however, its safety and efficacy in the acute stage remains unclear.

METHODS

This is a multicentric retrospective analysis of 15 consecutive acutely ruptured dissecting posterior circulation aneurysms treated with flow diverters. The primary end point was favorable aneurysm occlusion, defined as OKM C1-3 and D (O'Kelly Marotta scale). Secondary end points were procedure-related complications and clinical outcome.

RESULTS

Nine of 15 aneurysms (60%) arose from the intradural portion of the vertebral artery, 3 were located on the posterior inferior cerebellar artery and 1 each on the anterior inferior cerebellar artery, posterior cerebral artery, and basilar artery. Flow diverter placement was technically successful in 14 of 15 cases (93%). After endovascular treatment, none of the ruptured aneurysms rebled. Median clinical follow-up was 217 days and median angiographic follow-up was 203 days. Favorable occlusion was observed in 7 of 14 aneurysms (50%) directly after flow diverter placement; of those, 5 were completely occluded (36%). Seven patients (47%) with poor-grade subarachnoid hemorrhage died in the acute phase. Favorable clinical outcome (modified Rankin scale ≤2) was observed in 4 of 15 patients (27%) and a moderate outcome (modified Rankin scale 3/4) was observed in 5 of 15 patients (33%). All aneurysms showed complete occlusion at follow-up.

CONCLUSIONS

Flow diverters might be a feasible, alternative treatment option for acutely ruptured dissecting posterior circulation aneurysms and may effectively prevent rebleeding. Larger cohort studies are required to validate these results.

Surgical case series of multiple aneurysms: A single-centre experience of 16 years

INTRODUCTION

Multiple aneurysms are present in 10% in patients with intracranial aneurysms. An analysis of the literature, focusing on the different treatments, and a description of our experience are performed.

PRESENTATION OF CASE SERIES

A surgical series with multiple intracranial aneurysms from 2000 to 2016, describing demographic, radiological and clinical features, is showed. In all patients a pre- and post-operative angiography was performed and surgical treatment, based on accurate indications, provided good outcomes in most cases.

DISCUSSION

Successful treatment of multiple intracranial aneurysms can be achieved by an interdisciplinary approach and the main factors influencing surgical treatment are discussed.

CONCLUSIONS

Surgery always remains a definitive treatment and, considering intrinsic lesional features and patient's characteristics, it offers good results for intracranial multiple aneurysms.

Collagen type-I A2 gene polymorphisms and susceptibility to intracranial aneurysms: a meta-analysis of genetic association studies

BACKGROUND

The development, evolution and rupture of intracranial aneurysms are in part related to genetic factors. The role of collagen type-I a2 genetic polymorphisms has not been clarified yet.

MATERIAL AND METHODS

A meta-analysis was realized by means of a genotype model-fitting process (allele contrast, recessive, dominant, additive and co-dominant), and a model-free approach using the generalized odds ratio. The latter was assessed in association to the degree of dominance (h-index).

RESULTS

No statistically significant association was documented between EX28 G>C collagen type-I a2 variant and intracranial aneurysms (generalized odds ratio = 1.23, 95% confidence interval = 0.57, 2.63). Significant associations between INT46 T>G collagen type I a2 variant and intracranial aneurysms were documented in three models, the dominant [0.52 (0.38, 069)], the co-dominant [0.50 (0.32, 0.78)] and the allele contrast models [0.63 (0.49, 0.82)]. The generalized odds ratio was estimated to be as high as 1.94 (1.23, 3.06). The degree of dominance (h-index = -1.54) indicated that the TG genotype was characterized by lower risk of developing intracranial aneurysms compared to the TT genotype.

CONCLUSIONS

The available literature data demonstrated that there is no association of collagen type-(2a) and intracranial aneurysms, through EX28 G>C (rs42524) polymorphism according to the model-fitting process and the model-free approach. Regarding the INT46 T>G (rs2621215) polymorphisms, the latter models indicated that there could be a protective effect of the G-allele against the development of intracranial aneurysms. However, the majority of studies are from East Asia, therefore the results are applicable primarily to that patient population.

CDKN2BAS gene polymorphisms and the risk of intracranial aneurysm in the Chinese population

Background

CDKN2BAS gene polymorphisms has been shown to correlation with intracranial aneurysm(IA) in the study of foreign people. The study, the author selected the Chinese people as the research object to explore whether CDKN2BAS gene polymorphisms associated with Chinese patients with IA.

Methods

We selected 200 patients(52.69 ± 11.50) with sporadic IA as experimental group, 200 participants(49.99 ± 13.00) over the same period to the hospital without cerebrovascular diseases as control group. Extraction of peripheral blood DNA, applying polymerase chain reaction(PCR)-ligase detection reaction (LDR) identified CDKN2BAS Single nucleotide polymorphism(SNP) locus genotype: rs6475606, rs1333040, rs10757272, rs3217992, rs974336, rs3217986, rs1063192. The differences in allelic and genotype frequencies between the patient and control groups were evaluated by the chi-square test or Fisher’s exact tests.

Results

The genotype of rs1333040 and rs6475606 shown association with sporadic IA(X² = 8.545, P = 0.014; X² = 10.961, P = 0.004; respectively);the C allele of rs6475606 showed reduction the occurrence of IA; the rs1333040 and rs6475606 associated with hemorrhage, the C allele of rs1333040 could lower the risk of hemorrhage, and rs6475606 will not, rs1333040 also associated with aneurysm size.

Conclusion

Our research shows that variant rs1333040 and rs6475606 of CDKN2BAS related to the Chinese han population of sporadic IAs occurs. This study confirms the association between CDKN2BAS and IAs.

Arterial aneurysms associated with intracranial dural arteriovenous fistulas: epidemiology, natural history, and management. A systematic review

Arterial aneurysms are uncommon among patients with dural arteriovenous fistulae (DAVFs), and there is limited information available to guide treatment decisions in such cases. We performed a systematic review of the literature, including a case of a DAVF associated with a flow-related intraorbital ophthalmic artery (OA) aneurysm that we have recently managed. The purpose of our study was to clarify epidemiology, natural history, and management of these lesions. A total of 43 published cases of DAVF associated aneurysms were found in 26 studies on the topic. Anterior cranial fossa was the most common location (40%), and ethmoidal branches were the most common arterial feeders (55%). In about 63% of cases, the aneurysm was located on artery unrelated to DAVF supply. Approximately 10% of intracranial DAVFs were associated with aneurysms located in the intraorbital OA. Overall, 70% of lesions were Borden type III, and 50% of patients presented with hemorrhage. In approximately 17% of cases, the source of bleeding was a feeding artery aneurysm. All of the reported intraorbital OA aneurysms associated with DAVFs remained stable during follow-up. DAVF associated aneurysms are fairly rare. Anterior cranial fossa location and direct cortical venous drainage are common among these lesions. The aneurysms are less likely to be located on feeding arteries, and hemorrhagic presentation related to flow-related aneurysm rupture is uncommon.

A Prospective Multicenter Trial of the TransForm Occlusion Balloon Catheter: Trial Design and Results

Background and Purpose

Adjunctive treatments like balloon-assisted coil embolization (BACE) and stent-assisted coil embolization play a major role in the treatment of wide-neck and large intracranial aneurysms. The TransForm™ Occlusion Balloon Catheter (TOBC) registry is intended to evaluate the safety, efficacy, and efficiency of BACE using the TOBC.

Method and Study Design

The TOBC registry is a prospective multicenter registry trial. Seven sites in the USA and 1 site in Spain participated and enrolled 81 patients.

Results

The performance and safety of the TOBC was evaluated based on scoring for different variables. Scores were measured using a semiquantitative rating scale (1 = excellent, 5 = poor). The mean scores for these variables were as follows: visibility under fluoroscopy, 1.8; ability to reach the intended site, 1.6; stability during first positioning, 1.5; stability during inflation, 1.6; stability during deflation, 1.6; ability to temporarily stop flow, 1.6; and ability to assist in coil embolization, 1.7. The mean inflation and deflation times were 4.9 and 5.6 s, respectively. Complete obliteration of the aneurysm (Raymond class I) was achieved in 69.4% of the BACE cases. Thrombus formation occurred in 4/81 (4.8%) of the cases. In all cases, the thrombus resolved with medications, no patient suffered an infarction, and an underlying hypercoagulable state from subarachnoid hemorrhage was considered a contributing factor. Vessel rupture occurred in 1/81 (1.2%) of the cases, but was unrelated to TOBC use.

Conclusion

BACE using the TOBC is safe and effective. All variables assessed for performance showed good-to-excellent results.

Proximal Stenosis Is Associated with Rupture Status in Middle Cerebral Artery Aneurysms

BACKGROUND

Hemodynamic factors impact cerebral aneurysm development and progression. Parent vessel architectural features, such as caliber, curvature, and angle, can affect downstream pressure and shear stress.

OBJECTIVE

To investigate the association between proximal parent vessel stenosis and aneurysm rupture status at the middle cerebral artery (MCA) bifurcation.

METHODS

Catheter 3-dimensional rotational angiographic datasets from 69 Japanese patients with MCA aneurysms (58 unruptured/11 ruptured) were analyzed. The narrowest cross-sectional area of the M1 segment was evaluated through equidistant cross-sectional plane cuts along the M1 length. The degree of stenosis relative to M1 size (StenosisIndex) and the distance from stenosis to the aneurysm neck (StenosisAnDist) were statistically evaluated. The effects of StenosisIndex and StenosisAnDist were determined in parametric aneurysm models with/without stenosis using computational fluid dynamic and fluid-structure interaction simulations.

RESULTS

MCA harboring ruptured aneurysms had significantly greater StenosisIndex (0.31 ± 0.21 vs. 0.17 ± 0.14, P = 0.01), indicative of greater narrowing, and shorter StenosisAnDist (4.26 ± 1.91 vs. 6.94 ± 4.06 mm, P = 0.02) compared with unruptured aneurysms. Multivariate analysis combining StenosisIndex and StenosisAnDist resulted in P = 0.003, area under the curve = 0.81 (80% sensitivity, 74% specificity). Computational fluid dynamic and fluid-structure interaction simulations identified a synergetic effect of high stenosis and short StenosisAnDist in inducing greater aneurysm inflow velocity and deeper jet penetration, greater dome pressure, and greater tensile stress in the aneurysm wall.

CONCLUSIONS

Ruptured status in bifurcation MCA aneurysms was associated with severity of proximal M1 stenosis and its proximity to the aneurysm neck, a novel risk factor, which acts by increasing aneurysm dome wall tension, and should be considered in investigations of rupture risk stratification.

Comparative transcriptome analysis reveals involvement of TLR-2 signaling in the pathogenesis of intracranial aneurysm

In this study, we collected and analyzed 15 aneurysmal and 17 superficial temporal artery (STA) specimens from 32 Chinese patients with intracranial aneurysm. Total RNA was extracted and reverse transcribed to cDNA, and genome-wide expression profiling was performed by using the Affymetrix Human Genome U133 Plus 2.0 Array which allows a total number of 38,500 genes to be analyzed at the same time. Real-time RT-PCR was performed to verify the expression level of 8 selected genes. We found significant up-regulation of the TLR-2 gene. This result suggests that TLR-2 plays a key role in the formation of intracranial aneurysm in a Chinese population. To our knowledge, this study is the first to use the Human Genome U133 Plus 2.0 Array to analyze the gene expression profiles in Chinese patients with intracranial aneurysm.

OsiriX software as a preoperative planning tool in cranial neurosurgery: A step-by-step guide for neurosurgical residents

Background:

OsiriX (Pixmeo, Switzerland) is an open-source Digital Imaging and Communications in Medicine (DICOM) viewer that is gaining more and more attention in the neurosurgical community because of its user-friendly interface, powerful three-dimensional (3D) volumetric rendering capabilities, and various options for data integration. This paper presents in detail the use of OsiriX software as a preoperative planning tool in cranial neurosurgery.

Methods:

In January 2013, OsiriX software was introduced into our clinical practice as a preoperative planning tool. Its capabilities are being evaluated on an ongoing basis in routine elective cranial cases.

Results:

The program has proven to be highly effective at volumetrically representing data from radiological examinations in 3D. Among its benefits in preoperative planning are simulating the position and exact location of the lesion in 3D, tailoring the skin incision and craniotomy bone flap, enhancing the representation of normal and pathological anatomy, and aiding in planning the reconstruction of the affected area.

Conclusion:

OsiriX is a useful tool for preoperative planning and visualization in neurosurgery. The software greatly facilitates the surgeon's understanding of the relationship between normal and pathological anatomy and can be used as a teaching tool.

Management of Unruptured Intracranial Aneurysms

Unruptured intracranial aneurysms (UIA) occur in approximately 2-3 % of the population. Most of these lesions are incidentally found, asymptomatic and typically carry a benign course. Although the risk of aneurysmal subarachnoid hemorrhage is low, this complication can result in significant morbidity and mortality, making assessment of this risk the cornerstone of UIA management. This article reviews important factors to consider when managing unruptured intracranial aneurysms including patient demographics, comorbidities, family history, symptom status, and aneurysm characteristics. It also addresses screening, monitoring, medical management and current surgical and endovascular therapies.

The quality assessment of clinical practice guidelines for intracranial aneurysms: a systematic appraisal

Intracranial aneurysms are common in adults. The relevant guidelines for patients with intracranial aneurysms aim to standardize the clinical practice and decision making for these patients. However, their management is controversial, and the quality of the guidelines has not been assessed. We aim to evaluate the quality of the guidelines for intracranial aneurysms as well as to compare and analyze the recommendations between different guidelines. Systematic searches were conducted to identify the guidelines for intracranial aneurysms from general electronic and guideline databases. Two independent reviewers identified the guidelines and extracted the data, and four reviewers independently evaluated the eligible guidelines through the AGREE II tool. Agreement among reviewers was measured using the intraclass correlation coefficient. A total of 12 guidelines, which were published from 1997 to 2016, were included. The agreement among reviewers was high (intraclass correlation coefficient, 0.85 (95% CI: 0.8-0.89)). The mean scores of six domains ranged from 16.5 to 57.5% (scope and purpose 57.5% (39-68%); stakeholder 30.8% (19-46%); rigor 31.9% (19-52%); clarity 57.2% (42-79%); applicability 24.9% (16-42%); and editorial independence: 16.5% (0-58%)). Furthermore, 202 recommendations related to intracranial aneurysms were collected from the included guidelines. Of these, 143 reported the quality of evidence and/or strength, and 119 reported both the quality of evidence and the strength. Of the 119 recommendations, there were six class A and 20 class B recommendations based on level III evidence. There were 12 recommendations in which the contents were similar between different guidelines and two recommendations with the opposite contents. The AGREE II scores of the guidelines for intracranial aneurysms were relatively low. The majority of recommendations were rated as classes A and B and based on levels II and III evidence. Approximately a fifth of strong recommendations was based on a low quality of evidence without interpretation or explanation.

Quantitative Analysis of Intracranial Vertebrobasilar Dissecting Aneurysm with Intramural Hematoma After Endovascular Treatment Using 3-T High-Resolution Magnetic Resonance Imaging

OBJECTIVE

Quantitative measurements of intracranial vessel walls are reliable in 3-T high-resolution magnetic resonance imaging (HR-MRI). However, few reports have assessed the arterial wall after endovascular treatment (EVT) by 3-T HR-MRI. This study aimed to quantitatively analyze vessel walls in vertebrobasilar artery dissecting aneurysms after EVT.

METHODS

From May 2012 to December 2015, a total of 21 patients with 21 intracranial vertebrobasilar dissecting aneurysms (VBDAs) were enrolled in this consecutive study. All the VBDAs were characterized by intramural hematomas (IMHs ≥5 mm) and treated with reconstructive EVT. Images of preoperative and follow-up 3-T HR-MRI were used to evaluate the arterial wall. The relative signal intensity (RSI) of IMHs was quantified on T1-weighted imaging (T1WI) and magnetization-prepared rapid acquisition gradient-echo (MPRAGE).

RESULTS

Angiographic follow-up was performed for a mean of 9.19 ± 3.22 months. According to angiographic results at follow-up, 21 patients were divided into 2 groups (progressive group, n = 6; stable group, n = 15). In the progressive group, RSI of IMHs was significantly increased on MPRAGE of follow-up 3-T HR-MRI compared with that before treatment (P < 0.05), and the difference was not significant on T1WI. However, in the stable group, RSI of IMHs was significantly reduced after treatment (P < 0.05).

CONCLUSIONS

Persistent high signal intensity of IMHs in VBDAs after reconstructive EVT may be associated with the progression of VBDAs. It may also indicate an unsteady state of the aneurysm, which suggests that reconstruction of the parent artery is not satisfactory.

Flow diversion with the pipeline embolization device for patients with intracranial aneurysms and antiplatelet therapy: A systematic literature review

Flow diversion with the Pipeline Embolization Device (PED) is reported as a safe and efficient treatment for patients with intracranial aneurysms; however, literature discussing the antiplatelet (APT) regimen used before and after the PED is limited. Our aim was to systematically review and summarize available data regarding the APT regimen and the platelet function test (PFT) that was used. We also sought to provide an overview of the aneurysm morphologies and adverse event rates associated with the PED use. This systematic review was conducted according to the PRISMA statement and eligible studies were identified through search of the PubMed and Cochrane databases. We reviewed 28 studies, involving 1556 patients that underwent aneurysm treatment with the PED. The preprocedural aspirin (ASA) 300- 325mg (2-14days) combined with clopidogrel 75mg (3 to >10days) were used as a treatment strategy in 61.7% of patients and ASA 81mg with clopidogrel 75mg for 5-10days for 27%. Patients who received low versus high dose pre-PED ASA, were at less risk for a hemorrhagic event (0.7% versus 3.3%, p=0.053); however no statistical significance was reached. There was also lack of relationship between patients that received low versus high preprocedural ASA in terms of thromboembolic events. Regarding postprocedural APT, ASA (>6months) and clopidogrel (3- 12 months) was the regimen of choice for 93% of patients. Most studies conducted at least one PFT, most common being the VerifyNow. The most frequently reported target P2Y12 Reaction unit (PRU) and Aspirin Reaction Unit (ARU) values were <230 and <550 respectively. There was no statistically demonstrable difference in regards to thrombotic events between centers that conducted at least one PFT and centers that did not test their patients with a PFT. The overall rates of symptomatic thrombotic episodes were 6.6% and hemorrhagic were 3%. The pre- and post-PED APT dose and duration varies across different institutions. More prospective studies are needed to compare the efficacy of different APT agents and reach conclusions regarding use of PFT and platelet reaction values in order to decrease hemorrhagic and thromboembolic complications associated with the PED.

Rabbit aneurysm models mimic histologic wall types identified in human intracranial aneurysms

Background

Semiquantitative scales correlate histopathologic findings in the walls of human aneurysms with rupture status.

Objective

To apply a semiquantitative scale to the rabbit elastase-induced aneurysm model to determine whether rabbit histologic types mimic the full range of histologic subtypes of humans.

Materials and methods

Twenty-seven elastase-induced female rabbit aneurysms were studied, harvested at 2 weeks (n=5) and 12 weeks (n=22). Paraffin-embedded sections received hematoxylin-eosin and Verhoeff-Van Gieson staining. Immunohistochemistry was performed for α-smooth muscle actin and CD31 for endothelial cells. A semiquantitative scale was used for scoring based on human aneurysm tissue, divided into four subtypes according to cellular and extracellular matrix findings: type A, linear organized smooth muscle cells (SMCs) and intact endothelium; type B, thickened wall with disorganized, proliferating SMCs; type C, thick, collagenized and hypocellular wall with or without organizing thrombosis, and type D, extremely thin, hypocellular wall. Separate scoring was performed of the aneurysm neck and proximal and distal zones.

Results

Findings compatible with all subtypes of human aneurysm tissue were identified. Types A and C were found in 13 (48%) and 11 (41%) of 27 aneurysms and in the proximal and distal wall at both time points. Type B was found in 16 aneurysms (59%), exclusively at the neck at both time points; type D, in 14 aneurysms (52%), exclusively at proximal and distal zones of 12-week aneurysms.

Conclusions

The wall of elastase-induced rabbit aneurysm demonstrates histologic findings similar to the four categories of human cerebral aneurysms based on cellular and extracellular wall content.

A Novel Flow Diverter (Tubridge) for the Treatment of Recurrent Aneurysms: A Single-Center Experience

Objective

The Tubridge flow diverter (FD) is a novel device aimed at reconstructing the parent artery and occluding complex aneurysms. Retreatment of recurrent aneurysms using the FD is challenging. We report our initial experience in the repair of aneurysm recurrence with the FD.

Materials and Methods

A database was reviewed prospectively, and 8 patients with 8 recurrent aneurysms (mean size, 16.7 mm) were identified. Four aneurysms had previously ruptured. The previous aneurysm treatment consisted of coiling in 1 aneurysm and single-stent-assisted coiling in 7 aneurysms. The procedural complications and clinical and angiographic outcomes were analyzed.

Results

Six aneurysms were treated by using a single Tubridge FD alone, while the remaining 2 were treated with FD + coiling. The immediate results of the 8 aneurysms were that they all showed incomplete occlusion. Neither major ischemic nor hemorrhagic complications occurred; however, 1 patient experienced a vasospasm. Follow-up angiographies were available for 7 aneurysms; the mean follow-up was 16.9 months (7–36 months). Five aneurysms were completely occluded, whereas 2 had a residual neck. Severe asymptomatic stenosis of 1 parent artery of a vertebral artery dissecting aneurysm was found. All visible branches covered by the FD were patent. All patients were clinically assessed as having attained a favorable outcome (modified Rankin Scale score ≤ 2) at discharge and follow-up.

Conclusion

In selected patients, the Tubridge FD can provide a safe and efficient option for the retreatment of recurrent aneurysms. Nevertheless, attention should be paid to several technical points.

Unruptured Paraclinoid Aneurysm Treatment Effects on Visual Function: Systematic Review and Meta-analysis

OBJECTIVE

Postoperative visual outcomes following repair of unruptured paraclinoid aneurysms (UPAs) are not well defined. We aim to investigate the influence of treatment modality on visual function.

METHODS

A systematic literature analysis using the Ovid Medline and EMBASE databases was performed, encompassing English language studies (published between 1996 and 2016) reporting treatment outcomes for UPAs. Rates of visual morbidity (new, permanent postoperative deficit, worsening preoperative deficit); angiographic (occlusion, recurrence, retreatment) and clinical outcomes (death, disability, post-treatment subarachnoid hemorrhage) were recorded. Random effects meta-analysis was performed.

RESULTS

Twenty-eight studies reported visual outcomes, with data for 1013 endovascular and 691 microsurgical patients. In patients with normal vision undergoing elective repair of UPAs, rates of postoperative visual morbidity were higher following microsurgical (10.8%; 95% confidence interval [CI] 8.5-13.7) than endovascular (2.0%; 95% CI 1.2-3.2) interventions, P < 0.001. In those presenting with preoperative visual impairment, surgery was associated with a modest advantage in visual recovery compared with endovascular therapies (65.2% vs. 48.9%, P < 0.03). There were no differences in visual morbidity following treatment with any of the endovascular modalities. Meta-analysis of comparative studies suggested a trend toward poor visual (ES = 0.42; 95% CI 0.08-2.09) and clinical outcomes (ES = 0.57; 95% CI 0.07-4.44) following microsurgery and a trend toward angiographic recurrence (ES = 2.52; 95% CI 0.80-7.90) and retreatment (ES = 1.62; 95% CI 0.46-5.67) after endovascular interventions.

CONCLUSION

In patients with normal vision undergoing repairs for UPAs, there is a positive correlation between visual outcomes and endovascular treatments. When visual compromise is present, surgery provided modest advantage in visual recovery. However, definitive conclusions were not possible due to data heterogeneity.

One-year efficacy and safety of the Trufill DCS Orbit and Orbit Galaxy detachable coils in the endovascular treatment of intracranial aneurysms: Results from the TRULINE study

Background and purpose No series reported the mid-term results of Trufill DCS Orbit and Orbit Galaxy detachable coils with independent evaluation. We present the one-year safety and efficacy of these coils in real-life routine clinical practice. Methods A total of 167 patients with 167 aneurysms (39.1% ruptured) were enrolled in the prospective TRULINE study. The primary endpoint was the safety, assessed by the combined morbidity-mortality rate observed since the time of the procedure and up to one-year follow-up. For safety, primary analyses were performed on intent-to-treat population (attempted coils procedure) and all adverse events have been reviewed by an independent Data Safety Monitoring Board. For efficacy, primary analyses were performed on the per-protocol population (patients treated with more than 70% of Trufill coils and not retreated during the follow-up period) and an independent core laboratory evaluated angiographic results. Results At one-year post-procedure, neurologic impairment was observed in 6.5% (95% confidence interval: 3.5-11.8) of the patients, and 2.6% (95% confidence interval: 1.0-6.8) had a permanent neurological deterioration. Three deaths were observed, unrelated to the procedure or coils. At one year, complete occlusion was seen in 52 aneurysms (54.2%), neck remnant in 28 aneurysms (29.2%), and aneurysm remnant in 16 aneurysms (16.7%). During the one-year follow-up, the overall incidence of recurrence was 30.2% with a mean interval of 13.8 ± 4.5 months and the retreatment for major recanalization was needed in nine patients (6.3%). Conclusions The TRULINE study confirms that endovascular coiling with Trufill DCS Orbit and Orbit Galaxy detachable coils is safe and effective.

Shear Stress Induces Phenotypic Modulation of Vascular Smooth Muscle Cells via AMPK/mTOR/ULK1-Mediated Autophagy

Phenotypic modulation of vascular smooth muscle cells (VSMCs) is involved in the pathophysiological processes of the intracranial aneurysms (IAs). Although shear stress has been implicated in the proliferation, migration, and phenotypic conversion of VSMCs, the molecular mechanisms underlying these events are currently unknown. In this study, we investigated whether shear stress(SS)-induced VSMC phenotypic modulation was mediated by autophagy involved in adenosine monophosphate-activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)/Unc-51-like kinase 1 (ULK1) pathway. The results show that shear stress could inhibit the expression of key VSMC contractile genes and induce pro-inflammatory/matrix-remodeling genes levels, contributing to VSMCs phenotypic switching from a contractile to a synthetic phenotype. More importantly, Shear stress also markedly increased the levels of the autophagy marker microtubule-associated protein light chain 3-II (LC3II), Beclin-1, and p62 degradation. The autophagy inhibitor 3-methyladenine (3-MA) significantly blocked shear-induced phenotypic modulation of VSMCs. To further explore the molecular mechanism involved in shear-induced autophagy, we found that shear stress could activate AMPK/mTOR/ULK1 signaling pathway in VSMCs. Compound C, a pharmacological inhibitor of AMPK, significantly reduced the levels of p-AMPK and p-ULK, enhanced p-mTOR level, and finally decreased LC3II and Beclin-1 level, which suggested that activated AMPK/mTOR/ULK1 signaling was related to shear-mediated autophagy. These results indicate that shear stress promotes VSMC phenotypic modulation through the induction of autophagy involved in activating the AMPK/mTOR/ULK1 pathway.

Intracranial aneurysms in patients with autosomal dominant polycystic kidney disease: prevalence, risk of rupture, and management. A systematic review

BACKGROUND

Autosomal dominant polycystic kidney disease (ADPKD) is a genetic disorder associated with high incidences of intracranial aneurysms. We performed a systematic review with the purpose of clarifying the prevalence, risk of rupture, and appropriate management of intracranial aneurysms in the ADPKD population.

METHOD

PRISMA guidelines were followed. We conducted a comprehensive literature search of three databases (PubMed, Ovid MEDLINE, and Ovid EMBASE) on all series reporting ADPKD patients with intracranial aneurysms.

RESULTS

Our systematic review included 16 articles with a total of 563 patients with ADPKD and intracranial aneurysms. The prevalence of unruptured aneurysms was 11.5% (95% CI = 10.1-13%), whereas 1.9% (95% CI = 1.3-2.6%) of aneurysms were ruptured. Hypertension was present in 79.3% of patients with ADPKD and renal impairment in 65%. The mean size of ruptured aneurysms was slightly higher than unruptured (6 mm vs. 4.4 mm). The most common locations of unruptured and ruptured aneurysms were the ICA (40.5%) and MCA (45%), respectively. Asymptomatic patients studied with four-vessel angiography experienced 25% transient complications. Overall, 74% unruptured aneurysms were surgically treated with lower complication rates compared to endovascular treatment (11% vs. 27.7%). Among conservatively treated aneurysms, 2.9% ruptured at follow-up (rupture rate 0.4%/patient-year). Finally, the growth rate was 0.4% per patient-year, and the incidence of de novo aneurysm formation was 1.4% per patient-year.

CONCLUSIONS

The prevalence of unruptured intracranial aneurysms in the ADPKD population is approximately 11%. Given the non-negligible rate of procedural complications, the management of these patients must be cautious and individualised. The rupture rate appears comparable to that of the general population. On the other hand, the 1.4% rate per patient-year of de novo aneurysms is non-negligible. These findings should be considered when counselling ADPKD patients regarding the appropriate management of intracranial aneurysms.

Aneurysm rebleeding after placement of external ventricular drainage: a systematic review and meta-analysis

BACKGROUND

The association between external ventricular drainage (EVD) and aneurysm rerupture is still a controversial issue. We performed a systematic review and meta-analysis of published series reporting data of EVD placement in aneurysmal subarachnoid hemorrhage (SAH) with the aim to evaluate the relationship between ventricular drainage and aneurysm rebleeding.

METHOD

PRISMA/MOOSE guidelines were followed. The Newcastle-Ottawa Scale was used to assess the quality of the studies. We conducted a comprehensive literature search of three databases (PubMed, Ovid MEDLINE, and Ovid EMBASE) on series reporting patients with EVD placement and aneurysmal SAH. The reported studies were analyzed with a primary aim to calculate the strength of the association (odds ratio) between rebleeding and EVD placement in patients with SAH.

RESULTS

Our systematic review included 16 articles with a total of 6804 patients with SAH of which 595 (8.7%) had aneurysmal rebleeding. Ventricular drainage was inserted in 19% of patients. Rebleeding occurred in 18.8% (95% CI = 16.4-20.6%) of patients requiring EVD and in 6.4% (95% CI = 5.8-7.1%) of patients who did not require EVD (OR = 3.92, p < 0.0001). The mean time between EVD placement and rebleeding was 1 h (range, 0-8 h). The maximal aneurysm diameter of patients with rerupture was larger when compared with patients without rerupture (9.9 mm vs. 7.5 mm; p < 0.04). High Fisher grades (III-IV) were present in 75% of patients with rerupture and in 60% of patients without aneurysmal rerupture (p < 0.0001).

CONCLUSIONS

Our study conclusively defined an association between EVD and rebleeding. However, the effective role of EVD in aneurysm rebleeding is insufficiently investigated in the literature. Other significant factors of rebleeding are usually observed in patients requiring ventricular drainage. According to our findings, a causal relationship between EVD and aneurysm rebleeding could be a plausible hypothesis, at least in certain cases.

Giant Intracranial Aneurysms: Surgical Treatment and Analysis of Risk Factors

OBJECTIVE

To study clinical outcome of giant intracranial aneurysms (diameter ≥25 mm) treated with different surgical modalities and to analyze factors affecting prognosis.

METHODS

A retrospective analysis was performed of 204 consecutive patients with giant intracranial aneurysms who underwent surgical treatment in our department from 1995 to 2008. Clinical outcome was evaluated with the Glasgow Outcome Scale.

RESULTS

Surgical modalities included direct aneurysm neck clipping in 102 patients (50.0%), parent artery reconstruction in 51 patients (25.0%), proximal artery ligation in 23 patients (11.3%; 4 patients combined with revascularization), trapping in 26 patients (12.7%), and wrapping in 2 patients (1.0%). Follow-up data were available for 181 patients (88.7%), with a mean follow-up period of 62 months (range, 12-164 months). A good outcome (Glasgow Outcome Scale score 5) was observed in 114 patients (63.0%), and a poor outcome (Glasgow Outcome Scale score 1-4) was observed in 67 patients (37.0%). Independent factors that affected prognosis were age and location of aneurysm. Older age (≥50 years) and location of aneurysm in posterior circulation were associated with poor outcome. In 85 patients with preoperative subarachnoid hemorrhage, patients with a higher Hunt and Hess grade (≥3) had a worse outcome compared with patients with a low Hunt and Hess grade (1 or 2). Surgical modalities and other factors were not significantly associated with clinical outcome.

CONCLUSIONS

Giant intracranial aneurysms are effectively treated with craniotomy and surgical treatment. Older age, aneurysm location in posterior circulation, and higher Hunt and Hess grade are risk factors affecting prognosis.

Dual- versus Single-Energy CT-Angiography Imaging for Patients Undergoing Intracranial Aneurysm Repair

BACKGROUND

The invasiveness and risk of thromboembolic complications of catheter angiography underline the need for alternative imaging modalities in patients following intracranial aneurysm (IA) repair. However, the overall image quality of existing noninvasive imaging modalities, such as single-energy CT angiography (SE-CTA), compromises its value in this respect.

OBJECTIVE

We prospectively investigated the value of a novel dual-energy CTA (DE-CTA) scanner and algorithm for assessing the degree of occlusion and parent vessel patency in patients following IA repair.

METHODS

A prospective cohort of 17 patients underwent DE-CTA imaging following surgical or endovascular IA repair. This dataset was matched with an identical historical cohort of 17 patients, who underwent IA repair and SE-CTA imaging. Beam-hardening artifacts, as a measure for objective imaging quality were analyzed based on the volume of a prolate ellipsoid, whereas subjective imaging quality at the IA site and corresponding parent vessels was rated by 2 independent neuroradiologists on a scale from 4 (excellent, no artifacts) to 1 (poor, severe artifacts).

RESULTS

Objective DE-CTA image quality was markedly higher, compared to SE-CTA in patients undergoing surgical (0.77 ± 0.23 vs. 10.91 ± 1.88 mL, respectively; p < 0.001) or endovascular (32.36 ± 10.62 vs. 107.63 ± 24.51 mL, respectively; p = 0.026) IA repair. Subjective image quality for DE-CTA was significantly improved compared to SE-CTA in the surgical group but not in the endovascular group. The calculated dose values for DE-CTA in our study remain markedly below the legally required radiation dose limits.

CONCLUSION

The imaging quality of DE-CTA, especially for patients undergoing surgical IA repair, is distinctly superior, compared to SE-CTA imaging. Therefore, DE-CTA may serve as a noninvasive alternative for assessing the IA occlusion rate and parent vessel patency.

Association between hemodynamics, morphology, and rupture risk of intracranial aneurysms: a computational fluid modeling study

The objective of the study was to examine the correlations between intracranial aneurysm morphology and wall shear stress (WSS) to identify reliable predictors of rupture risk. Seventy-two intracranial aneurysms (41 ruptured and 31 unruptured) from 63 patients were studied retrospectively. All aneurysms were divided into two categories: narrow (aspect ratio ≥1.4) and wide-necked (aspect ratio <1.4 or neck width ≥4 mm). Computational fluid dynamics was used to determine the distribution of WSS, which was analyzed between different morphological groups and between ruptured and unruptured aneurysms. Sections of the walls of clipped aneurysms were stained with hematoxylin–eosin, observed under a microscope, and photographed. Ruptured aneurysms were statistically more likely to have a greater low WSS area ratio (LSAR) (P = 0.001) and higher aneurysms parent WSS ratio (P = 0.026) than unruptured aneurysms. Narrow-necked aneurysms were statistically more likely to have a larger LSAR (P < 0.001) and lower values of MWSS (P < 0.001), mean aneurysm-parent WSS ratio (P < 0.001), HWSS (P = 0.012), and the highest aneurysm-parent WSS ratio (P < 0.001) than wide-necked aneurysms. The aneurysm wall showed two different pathological changes associated with high or low WSS in wide-necked aneurysms. Aneurysm morphology could affect the distribution and magnitude of WSS on the basis of differences in blood flow. Both high and low WSS could contribute to focal wall damage and rupture through different mechanisms associated with each morphological type.

Leo stent for endovascular treatment of intracranial aneurysms: very long-term results in 50 patients with 52 aneurysms and literature review

INTRODUCTION

The Leo stent was the first retrievable stent for endovascular treatment of intracranial aneurysms (IAs). We report our experience with this device with emphasis on very long-term follow-up.

METHODS

This study was approved by authors' ethical committee. A retrospective review of our prospectively maintained database identified all patients treated for a saccular IA with this stent in our institution. Technical issues and immediate and long-term outcomes (at least 12 months) were evaluated.

RESULTS

Between 2004 and 2015, 50 patients with 52 IAs were identified. In two patients, the stent could not safely be placed (failure rate = 3.8%). Among 48 treated patients with 50 IAs, there were 44 women and 4 men (mean age, 53 years). Mean aneurysm diameter was 7.2 mm. All IAs but six were wide-necked. There was no immediate morbidity or mortality. Anatomical results included 76% complete occlusions, 22% neck remnants, and 2% incomplete occlusions. Mean follow-up was 50.2 months (range, 12-139 months). Two patients had delayed TIAs but long-term morbidity rate remained = 0%. At follow-up, occlusion was stable in 68% IAs, showed thrombosis in 12%, and recanalization in 20% IAs. Complementary treatment was required in 8% IAs. Final results showed 70% complete occlusions, 24% neck remnants, and 6% incomplete occlusions. Asymptomatic stent occlusion and significant stenosis occurred in one and two cases, respectively.

CONCLUSION

The Leo stent is safe and effective for treatment of wide-necked saccular IAs. Very long-term results show high rates of adequate and stable occlusion. Moreover, the stent is well tolerated.

Pterional or Subfrontal Access for Proximal Vascular Control in Anterior Interhemispheric Approach for Ruptured Pericallosal Artery Aneurysms at Risk of Premature Rupture

OBJECTIVE

Cases of a ruptured pericallosal artery aneurysm with a high risk of intraoperative premature rupture and technical difficulties for proximal vascular control require a technique for the early and safe establishment of proximal vascular control.

METHODS

A combined pterional or subfrontal approach exposes the bilateral A1 segments or the origin of the ipsilateral A2 segment of the anterior cerebral artery (ACA) for proximal vascular control. Proximal control far from the ruptured aneurysm facilitates tentative clipping of the rupture point of the aneurysm without a catastrophic premature rupture. The proximal control is then switched to the pericallosal artery just proximal to the aneurysm and its intermittent clipping facilitates complete aneurysm dissection and neck clipping.

RESULTS

Three such cases are reported: a ruptured pericallosal artery aneurysm with a contained leak of the contrast from the proximal side of the aneurysm, a low-lying ruptured pericallosal artery aneurysm with irregularities on its proximal wall, and a multilobulated ruptured pericallosal artery aneurysm with the parasagittal bridging veins hindering surgical access to the proximal parent artery. In each case, the proposed combined pterional-interhemispheric or subfrontal-interhemispheric approach was successfully performed to establish proximal vascular control far from the ruptured aneurysm and facilitated aneurysm clipping via the interhemispheric approach.

CONCLUSION

When using an anterior interhemispheric approach for a ruptured pericallosal artery aneurysm with a high risk of premature rupture, a pterional or subfrontal approach can be combined to establish early proximal vascular control at the bilateral A1 segments or the origin of the A2 segment.